Our verdict is Uncertain significance. Variant got 2 ACMG points: 2P and 0B. PM2
The NM_000548.5(TSC2):c.4025A>T(p.Gln1342Leu) variant causes a missense change involving the alteration of a conserved nucleotide. The variant allele was found at a frequency of 0.00000069 in 1,448,272 control chromosomes in the GnomAD database, with no homozygous occurrence. Variant has been reported in ClinVar as Uncertain significance (★).
TSC2 (HGNC:12363): (TSC complex subunit 2) This gene is a tumor suppressor gene that encodes the growth inhibitory protein tuberin. Tuberin interacts with hamartin to form the TSC protein complex which functions in the control of cell growth. This TSC protein complex negatively regulates mammalian target of rapamycin complex 1 (mTORC1) signaling which is a major regulator of anabolic cell growth. Mutations in this gene have been associated with tuberous sclerosis and lymphangioleiomyomatosis. [provided by RefSeq, May 2022]
Review Status: criteria provided, single submitter
Collection Method: clinical testing
The p.Q1342L variant (also known as c.4025A>T), located in coding exon 33 of the TSC2 gene, results from an A to T substitution at nucleotide position 4025. The glutamine at codon 1342 is replaced by leucine, an amino acid with dissimilar properties. This amino acid position is conserved. In addition, this alteration is predicted to be deleterious by in silico analysis. Since supporting evidence is limited at this time, the clinical significance of this alteration remains unclear. -